The present invention relates generally to a fracture reduction clamp for the temporary reduction or fixation of a fractured bone during a surgical procedure and more specifically, to an improved fracture reduction clamp which provides substantially complete circumferential compression of a fractured bone.
Fracture reduction clamps known in the art are used to adjust the tension of a strap or wire surrounding a fractured bone. Known fracture reduction clamps are generally clamp or plier shaped and generally provide only temporary and partial compression of a fractured bone. In use, known fracture reduction clamps generally only provide a two-point compression of a fractured bone and placement of a permanent fixation device onto a fractured bone being reduced generally requires release of the fractured bone by the reduction clamp.
While not clinically used as a fracture reduction clamp, a wire tensioner sold by Howmedica is used to implant a permanent fixation wire about a fractured bone. The bone tensioner of Howmedica comprises a tube-shaped body, a strap guiding head, an adjustable strap retainer and a tension adjustment handle attached to the body and threadably engaged with the strap retainer for adjusting the tension of a strap engaged with the strap retainer and strap guiding head.
The wire tensioner sold by Howmedica generally operates as follows. A strap is passed between a bone having a fracture and the muscle surrounding the bone. The strap is then looped completely around the fractured bone and each end is optionally laced through a crimping sleeve. Each end is then laced through a wheeled end of a strap guiding head and through an adjustable strap retainer. The looping of the wire about the bone provides permanent circumferential compression of the fractured bone when the crimping sleeve is crimped onto the wire. The struts comprising the strap guiding head generally do not grip or resiliently contact the fractured bone. In order to tighten the wire about the bone, a handle on the clamp is rotated thereby displacing the strap retainer further from the fractured bone and tightening the strap surrounding the fractured bone. As the strap tightens about the fractured bone, the bone fragments align and the fracture is reduced. The crimping sleeve is then crimped onto the strap thereby permanently fixating the fractured bone. While the wire tensioner of Howmedica is not used as a fracture reduction clamp, it does share some structural similarity with the presently claimed fracture reduction clamp. However, were the Howmedica wire tensioner to be used in a fashion similar to the present fracture reduction clamp, it could not provide the substantially complete circumferential compression of the fractured bone both before and during placement of a permanent fixation device such as a plate or screw onto or into the fractured bone.
Known fracture reduction clamps generally reduce fractured bones by grasping the bone in a manner resembling pliers. None of the known fracture reduction clamps permit the placement of a bone fixation plate along side a fracture while a strap is tightly surrounding a major portion of the fractured bone, i.e., while maintaining substantially complete circumferential compression of the bone, and none of the known devices comprise a retractable spike in a strap guiding head of the fracture reduction clamp.
The present invention seeks to address the disadvantages present in fracture reduction clamps known in the art. The fracture reduction clamp can provide substantially complete circumferential compression of a fractured bone while a permanent fixation device is being implanted between the bone and a strap guiding head of the device. The present fracture reduction clamp can provide an orthopedic surgeon the advantages of: reduced overall surgery time; reduced time in which the patient is under anesthesia; reduced blood loss by the patient; reduced stress on the fractured bone and surrounding tissue; and rapid alignment of the fractured bone.
In one aspect, the present invention provides a fracture reduction clamp for tightening a strap about a fractured bone, said clamp comprising:
a substantially hollow tubular body having opposing first and second ends, a coextensive bore therethrough and two slots interposed said first and second ends and intersecting with said bore;
a handle rotatably engaged with said first end of said tubular body;
an externally threaded drive shaft which is fixedly engaged with said handle, disposed within said bore of said tubular body, substantially coaxial with said tubular body, and accessible through said two slots of said body;
a strap retainer which is threadably engaged with said drive shaft, is slidable with respect to said tubular body and extends through said two slots of said tubular body; and
a strap guiding head engaged with said second end of said body and comprising opposing, spaced apart, first and second strap guiding struts, each strut having a bore to permit passage of a strap therethrough;
wherein rotation of said handle causes displacement of said strap retainer with respect to said head.
In one embodiment, the fracture reduction clamp can be dismantled by hand into separate components. In another embodiment, the fracture reduction clamp comprises a retractable spike in the head and a thumbwheel to retract and extend the spike. The retractable spike can include a flattened shaft portion which engages a flattened bore portion in the head thereby prohibiting rotation of the spike when the thumbwheel is rotated to displace the spike with respect to the head.
The head of the fracture reduction clamp can include two or more struts having stepped ends for contacting a bone being reduced by the device.
The strap retainer will be adapted to receive and retain a strap that is being used to reduce a bone having a fracture.
The fracture reduction clamp will be adapted to provide substantially complete circumferential compression of a fractured bone, preferably both before and during implantation of a permanent bone fixation device, such as a plate or pin, into or onto the fractured bone, wherein the strap itself is not the permanent fixation device.
The spacing between the first and second strap guiding struts can be made adjustable. In addition, the first and second strap guiding struts can be hingedly mounted onto the strap guiding head.
Another aspect of the invention provides a fracture reduction clamp for tightening a strap about a bone having a fracture, said clamp comprising:
a strap guiding head comprising a spike and at least one strap guide;
a body having a first end engaged with said strap guiding head and a second end;
a rotatable drive engaged with said second end of said body; and
a strap retainer adapted to receive and retain a strap passed through said strap guide, said retainer being threadably engaged with said rotatable drive and slidable with respect to said body;
wherein:
said strap retainer is displaced with respect to said strap guiding head when said rotatable driver is rotated.
The strap guiding head can have a bifurcation point at which first and second struts join. The first and second struts can each comprise a strap guide adapted to permit passage of a strap therethrough. The strap guiding head can also comprise a retractable spike which is slidable with respect to said first and second struts. The spike can be made retractable by way of threads on the spike and a thumbwheel threadably engaged with said spike for retracting and extending said spike. The strap guiding head, retractable spike, thumbwheel, tubular body, rotatable drive and strap retainer can each be shaped as desired to optimize performance for a particular use.
Yet another aspect of the invention provides a method of reducing a fractured bone, said method comprising the steps of:
passing a strap around a fractured bone such that said strap surrounds at least a portion of said bone;
passing each of first and second ends of said strap through at least one strap guide in a strap guiding head of a fracture reduction clamp;
engaging each of said first and second ends of said strap with a strap retainer that is slidable with respect to said strap guiding head and is threadably engaged with a rotatable strap tensioner of said fracture reduction clamp; and
rotating said strap tensioner such that said strap retainer is displaced away from said strap guiding head thereby tightening said strap about said bone.
The method of the present invention can further comprise the steps of extending or retracting a retractable spike comprised within a strap guiding head used in the method of the invention. Since temporary bone reduction is used in preparation of semi-permanent or permanent bone fixation, the present method of the invention can include steps directed toward fixation of the reduced bone. The bone fixation can be effected with any of a number of available bone fixation apparatuses.
In another embodiment, the invention provides a kit for a fracture reduction clamp, said kit comprising:
at least one tubular body having first and second ends;
at least one strap retainer;
at least two different, removable and interchangeable strap guiding heads which are engageable with said first end of said body; and
at least one strap tensioner engageable with said second end of said body and operably engaged with said at least one strap retainer.
The kit of the present invention can independently comprise one or more of each of the individual components of a fracture reduction clamp as described herein. Strap guiding heads of the kit can independently include retractable spikes. The strap guiding heads can differ in dimensions, shape, use, presence or absence of spikes, and in other manners. The strap guiding heads can also include first and second struts having passages for passing a strap therethrough and/or having stepped ends for contacting the surface of a fractured bone being reduced. The individual components of a kit according to the invention can be assembled by hand to form at least one fracture reduction clamp.
Still another embodiment of the invention provides a fracture reduction clamp which together with a strap retained by said clamp is capable of providing substantially complete circumferential compression of a fractured bone before and during implantation of a permanent fixation device into or onto the fractured bone, wherein the strap need not completely encircle the fractured bone.
In this embodiment, the permanent fixation device can be implanted without significantly loosening the strap about the bone. This clamp can also comprise one or more of a spike and a pair of strap guiding struts for contacting the fractured bone during reduction of the fracture. The spike can be fixed or retractable with respect to the clamp. The clamp can also comprise a strap retainer and strap tensioner, and rotation of the strap tensioner can be made to result in tightening of the strap about the fractured bone when the strap is retained by the strap retainer.
Each aspect and embodiment of the invention provides unique and advantageous features which overcome the disadvantages of and which are substantially different than known devices and methods.
Other features, advantages and embodiments of the invention will be apparent to those skilled in the art by the following description, accompanying examples and appended claims.